Numifier

A C++ library to convert numbers from word representation to numbers.

Building with CMake

• create a build folder and navigate to it

mkdir buid 
cd build

• build the project

cmake ..  
cmake --build .  

• You can try the library using the build/demo app

Usage

• build the library, and link libNumifier.a with your project and include the Numifier.h header
• Create a parser object

numifier::WordParser parser;

• Parse an std::string with

std::string str = "fiftyonethousand";
int number = parser.parseNumber(str); //will return 51000

• The default language is English, but you can also parse hungarian numbers, and Roman numerals

int number = parser.parseNumber(str,numifier::LANGUAGE::HUNGARIAN);  
int number = parser.parseNumber(str,numifier::LANGUAGE::ROMAN_NUMERALS);

The algorithm

Step 1: Format the input string

Remove the spaces,hyphens and all the "and" words from the string for example the string "one thousand three hundred and twenty-four" will become "onethousandthreehundredtwentyfour"

Step 2 Segmentate the input string

-Split the input string along the selected language's trivial numbers:
For example the string onethousandthreehundredtwentyfour will become ["one","thousand","three","hundred","twenty","four"]
The resulting vector can be translating into an integer vector, using the language's lookup table, so the end result will be [1,1000,3,100,20,4]

Currently only English, Hungarian, and Roman Numerals are supported.

Step 3 Construct the number

If you splice the result array from Step2 along the maximum value, put the maximum in the root node of a binary tree, and repeat the process recursively on the left and right side of the array, and you should have a binary tree like this:
After construction the tree, with inorder-traversal multiply the root node with the left side, and add the right side, and the result should be the final parsed integer.